Asked whether Saudi Arabia would ever build nuclear weapons in an interview with US news channel CNN, Adel Al-Jubeir said the subject was “not something we would discuss publicly”.

Pressed later on the issue he said: “This is not something that I can comment on, nor would I comment on.”

The ambassador’s reticence to rule out a military nuclear programme may reignite concerns that the autocratic monarchy has its eye on a nuclear arsenal.

Western intelligence agencies believe that the Saudi monarchy paid for up to 60% of Pakistan’s nuclear programme in return for the ability to buy warheads for itself at short notice, the Guardian newspaper reported in 2010. Which countries have nuclear weapons?

The two countries maintain close relations and are sometimes said to have a special relationship; they currently have close military ties and conduct joint exercises.

The Saudi Arabian regime also already possesses medium-range ballistic missiles in the form of the Royal Saudi Strategic Missile Force.

In addition it has significant nuclear expertise in the form of a civilian nuclear programme of the kind Iran says it wants to develop.

In 2012 the Saudi Arabian government threatened to acquire nuclear weapons were neighbouring regional power Iran ever to do so.

“Politically, it would be completely unacceptable to have Iran with a nuclear capability and not the kingdom,” a senior Saudi source told The Times newspaper at the time.

The United States and other Western allies say a deal with Iran on its nuclear programme is possible. Iran denies it is building nuclear weapons.

The news comes days after Saudi Arabia launched a military operation in neighbouring Yemen aimed at suppressing a rebel group that is attempting to form a central government.

Saudi’s military operation against the advancing Shia Houthi group has been joined by Egyptian, Jordanian and Moroccan forces.